Multiple area piston means



FIG. I

Oct. 16, 1951 w, BENNETT 2,571,658

MULTIPLE AREA PISTON MEANS Filed July 22, 1946 g WILLIZ J EE E u 41. g

Patented Oct. 16, 1951 MULTIPLE AREA PISTON MEANS William H. Bennett, Mount Gilead, Ohio, assignor to H-P-M Development Corporation, Wilmington, DeL, a corporation of Delaware Application July 22, 1946, Serial No. 685,539

'7 Claims.

This invention relates to fluid operable apparatus and, particularly, to reciprocating fluid rams having booster rams and adjustments thereof.

The particular object of the present invention is to provide an improved and simplified adjusting mechanism for determining the position at which the booster ram becomes ineffective for high speed travel.

Another object is to provide a simplified arrangement for supporting a booster ram in a reciprocating fluid motor which eliminates screw threaded connections and the like while still retaining the adjustability of the said booster ram.

It is an object of this invention to provide a booster ram construction which is fully balanced at all times and which is adjustable to determine the length of travel of the main ram under the influence of the said booster ram.

These and other objects and advantages will become more apparent upon reference to the following description and the accompanying drawing in which:

Figure 1 is a longitudinal section through a machine having a reciprocating ram and a booster ram according to this invention in combination therewith;

Figures 2 and 3 are modified arrangements of the booster ram somewhat similar to the form disclosed in Figure 1;

Figure 4 is another modified form of a booster ram employing a spiral groove on the surface thereof for effecting adjustment of the booster stroke; and

Figure 5 is a view illustrating still another form which the booster ram may take according to this invention.

Referring to the drawing, ll! indicates a cylinder within which is reciprocable the plunger l2 having the main advancing area l4 and the smaller retracting area IS.

The ram I2 is bored as at I 8 to receive a booster plunger 20 which is rotatably supported in a bore 22 formed in the closed end of the cylinder I 0.

The booster plunger or ram has an axial bore 24 therein which is intersected by the radial passage 26 which communicates with the annular groove 28 at the closed end of the cylinder [0. The end of the booster ram is closed and has projecting therefrom a shaped projection 30 adapted for receiving a wrench for driving the said booster ram in rotation. The booster ram is retained in the bore 22 by the split ring 32 which fits within the groove 34 in the booster ram and which is clamped in a recess 36 by the clamping ring 38. This arrangement holds the booster ram in the cylinder Ill against reciprocation while permitting free rotation thereof by the portion 3!]. Suitable sealing means such as packing may be employed to prevent leakage around the booster.

Referring to Figure 1 it will be noted that a portion of the bore 18, as at 40, fits closely around the booster plunger so that normally fluid communication between the main area I4 of the plunger l2 and the bore 18 is prevented. The intersecting axial and radial bores 42 and 44 in the plunger I2 are operable to interconnect the area l4 and the bore l B when the end of the said radial bore 44 passes the end of the booster plunger 20.

Fluid is admitted to the booster plunger by a bore 48 in the end of the cylinder l l! which communicates with the groove 28 and, by the bores 26 and 24, with the bore I8. Fluid is supplied to the retracting means It for moving the plunger l2 to the left by the bore 50 in the said cylinder. In response to fluid supplied through the bores 48 and 50, the plunger 12 may be reciprocated and, during its advancing stroke, will move rapidly until the bore 44 is opened to the bore l8, whereupon the plunger l2 will move more slowly but with increased thrust.

For adjusting the position of the plunger [2 at which the end of the bore 44 is uncovered, the booster plunger 20 has an inclined end surface 46 thereon. The exact location of the position where fluid is admitted to the area It may be varied by rotating the plunger '20. It will be observed that the amount of this adjustment is determined by the angle of inclination of the surface 66 and that a rotation of the booster plunger covers the entire range of adjustment.

In Figures 2 and 3 there are shown modified arrangements wherein the end portion of the booster plunger 20 is shaped so that when the plunger end is in the close-fitting portion 40 of the bore I8, the hydraulic thrusts on the end portion thereof are balanced off. In Figure 2 this is accomplished by having the inclined surface 45 formed or" the two portions 46a which are oppositely disposed so that any lateral thrust generated on one thereof is balanced off by an equal and opposite thrust generated on the other thereof.

In Figure 3 a similar result is obtained :by arranging the surfaces ifib as shown so that the thrust on either thereof due to the pressure of the hydraulic actuating fluid being employed is balanced by the thrust on the other.

Figure 4 illustrates a still further modification wherein the booster plunger 26 has formed on the surface thereof a spiral groove 52 which preferably passes exactly once around the said plunger and communicates with the axial bore 24 thereof by the'drilled passages 5 which may be located at each end of the spiral channel 52. By causing the said channel to pass exactly once around the booster plunger, the plunger is fully,

hydraulically balanced at all times and all lateral thrusts thereon due to hydraulic pressure are eliminated. The groove 52 is of sufiicient width in the axial direction of the plunger 20 that a normal working stroke of the ram [2 can be had after the bore M communicates with the said groove. It will be understood that although the high pressure working stroke of the said ram is limited to the width of the groove 52, this is sufiicient for most work cycles.

In Figure 5 the booster plunger 20 has a portion thereof of reduced diameter as at 55, with the said portion 56 forming a spiral shoulder 58 which passes around the booster plunger.

It will be apparent that any of the foregoing modifications may be formed to provide for any desirable amount of adjustment in the booster stroke of the main plunger, the forms illustrated in Figures 1,.2 and 3 providing for 180 rotation of the booster plunger While the forms illustrated in Figures 4 and 5, provide for 360 rotation thereof.

.It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. In combination; a main plunger, a booster plunger telescoping said main plunger; means to supply actuating fluid through said booster plunger to the end thereof; channel means for connecting said plungers normally closed by said plungers when telescoped a predetermined amount and opened by said plungers when telescoped less than said predetermined amount; and an inclined end surface on said booster plunger operable to vary said predetermined amount when said plungers are rotated relatively.

2. In combination, a main plunger, a booster plunger telescoping said main plunger; means to supply hydraulic actuating fluid to said inner plunger; channel meansextending through said outer plunger for connecting said plungers and normally closed by said inner plunger, said channel being uncovered to connect said plungers in response to a predetermined relative movement thereof; and means of varying the exact amount of said predetermined movement comprising an inclined end surface on the end of said inner plunger, the said inner plunger being laterally, hydraulically balanced by dividing the said end surface into two oppositely inclined end portions.

3. In combination, inner and outer telescoping plungers; means to supply hydraulic actuating fluid to said inner plunger; channel means extending through said outer plunger for connecting said plungers and normally closed by said inner plunger, said channel being uncovered to I connect said plungers in response to a predetermined relative movement thereof; and means of varying said predetermined movement comprising an undercut on said inner plunger forming an axially varying shoulder therearound whereby 5:

determined amount and to be uncovered by said inner plunger when said plungers are telescoped less than said predetermined-amount; and means of varying the said predetermined amount comprising a spiral shoulder extending around the inner end of the said inner plunger, whereby relative rotation of said plungers varies said predetermined amount.

5. In combination, a cylinder, a main ram reciprocable in said cylinder; a bore in said main ram; a booster plunger closely fitting and extending into said bore; means rotatably supporting said booster plunger in said cylinder and operable to prevent axial movement thereof; passage means in said cylinder and said booster plunger for supplying actuating fluid to the said bore; a passage in said main ram connecting the, working area thereof with said bore and normally covered by said booster plunger, the said passage being uncovered in response to a predetermined advancing movement of said main ram; an inclined edge extending at least part way around said booster ram and continuously in communication with the open portion of said bore; and means of angularly positioning said booster plunger for determining the extent of said. predetermined advancing movement.

6. In combination, a main plunger; a. hollow booster plunger telescoping said main plunger; means to supply actuating fluid through said booster plunger to the end thereof; channel means for connecting said plungers normally closed by said plungers when telescoped a predetermined amount and opened by said plungers when telescoped less than said predetermined amount; and a surface on said booster plunger disposed in angular relation to the longitudinal and transverse axes of said booster plunger operable to vary said predetermined amount when said plungers are rotated relatively.

7. In combination, a main plunger; a hollow plunger telescoping said main plunger; means to supply actuating fluid through said booster plunger to the end thereof; channel means for connecting said plungers normally closed by said plungers when telescoped a predetermined amount and opened by said plungers when telescoped less than said predetermined amount; and a surface formed on the exterior of said booster plunger operable upon relative rotationof said plungers to vary said predetermined amount.

WILLIAM H. BENNE'I'I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,114,005 Tyler Apr. 12, 1938 2,191,882 Ernst Feb. 27, 1940 2,243,603 MacMillin May 27, 1941 2,293,334 Ernst Aug. 18, 1942 2,309,758 Ernst Feb. 2, 1943 2,404,611 Ashbaugh July 23, 1946' 2,410,001 Ashbaugh Oct. 29, 1946 2,437,077 Cole Mar. 2, 1948 2,526,809 Cole Oct. 24,1950

FOREIGN PATENTS Number Country Date 284,524 Germany May 28, 1915 464,891 Great Britain Apr. 27, 1937 

